Firefox is popular as a resource hog when too many tabs are opened it does consume resources,  Firefox’s about:cache page provides statistics about RAM and Disk cache, we do use Ctrl+Shift+Del shortcut to clear the history, Cache Status  add-on shows Firefox RAM cache and Disk Cache statistics on the Add-on Bar and lets you clear any one or both of them easily.

Cache Status

Related Memory Restart, allows to Restart Firefox if It’s Memory Usage is too High

Cache Status pulls Cache statistics for memory and disk devices from the about:cache page and displays the numbers on the Add-on Bar for easier view (enable the Add-on Bar from options). This information is automatically updated.  You can right-click on RAM Cache or Disk Cache icons and clear any one or both the cache.

You can set Maximum RAM cache and Disk Cache for  the program to allow. Cache Status automatically cleans cache when it reaches user specified level through its options.

Cache Status works with Firefox 1.5 –8.*.